Research outlined in this proposal involves the use of fourier transform ion cyclotron resonance (FTICR) and ion trap mass spectrometry in combination with collision induced dissociation (CID) and infrared multiphoton dissociation (IRMPD) for the characterization of carbohydrate structure. In the first portion specific goals include: Site specific analysis of functional group variants with particular emphasis on a) determining phosphorylation sites on oligosaccharides, b) stabilization of sialic acid moieties and site specific determination, c) determination of specific linkage sites of sulfation and sequence analysis of GAG heparan sulfate. The second part of this proposal addresses both the methods development for identifying structure and linkage position in arabinofuranoses as well as implementation of the method for characterization of mycolyl arobinogalactan (mAG) and lipoarabinomannan (LAM) extracted from mycobacteria. Most of the general protocol proposed incorporates the use of metal ions or metal-ligand systems to achieve the goal of structural elucidation. Methods development is dove-tailed with application of the methods to biologically isolated and relevant carbohydrates as collaborations with Drs. Gibson, Lowary, Cox and Sasisekharan.